Mining negative pressure sensor calibration device

Abstract

The utility model discloses a mine negative pressure sensor calibration device, which relates to the technical field of sensor calibration and comprises a U-shaped pressure gauge and an air bag ball which are connected through a three-way pipeline. The rest end of the three-way pipeline is connected with the air inlet end of the negative pressure sensor; an air outlet and an air inlet are formed in the airbag ball, the air outlet is connected with a three-way pipeline, and the air inlet communicates with the outside; an air outlet valve is arranged on the air outlet, is a one-way valve and is communicated in the direction from the air bag ball to the three-way pipeline; and a tail valve is arranged on the air inlet, is a one-way valve and is communicated in the direction from the outside to the air bag ball. The U-shaped pressure gauge, the air bag ball and the negative pressure sensor are connected through the three-way pipeline, so that the three parts are in an isobaric state; in the calibration process, an operator can visually observe the value of pressure applied to the negative pressure sensor through the U-shaped pressure meter, so that the pressure is accurately adjusted to 2.5 kpa, the calibration requirement of the KGY3A mining negative pressure sensor is met, and the calibration accuracy is improved.

Description

A calibration device for a negative pressure sensor used in mining Technical Field

[0001] This utility model relates to the field of sensor calibration technology, and in particular to a calibration device for a negative pressure sensor used in mining. Background Technology

[0002] Coal mine safety monitoring systems are crucial for ensuring safe production in coal mines. Mining negative pressure sensors, as key safety monitoring equipment, are primarily used to monitor the air pressure within the ventilation ducts of local ventilation fans. Their accuracy and sensitivity are vital for protecting miners' lives and promoting the sustainable development of the coal mining industry. However, negative pressure sensors, operating in the high humidity and dust environments underground for extended periods, are prone to zero-point drift or decreased sensitivity, leading to distorted monitoring data. This can result in false alarms of "insufficient air pressure," causing unnecessary production shutdowns, or missed alarms of actual hazards, potentially causing accidents. Therefore, negative pressure sensors require regular calibration.

[0003] According to the instruction manual for the KGY3A mining negative pressure sensor, a pressure of 2.5 kPa should be applied when calibrating the sensor and adjusting its accuracy. However, the manufacturer did not provide the corresponding pressure application equipment, and other manufacturers also lack the necessary calibration devices and pressure application equipment. Common mechanical pressure application devices are difficult to control and can easily damage the negative pressure sensor, making the calibration of the negative pressure sensor extremely challenging. Summary of the Invention

[0004] The purpose of this invention is to provide a calibration device for a mine negative pressure sensor, which is suitable for calibrating mine negative pressure sensors and meets the calibration requirements of the KGY3A mine negative pressure sensor.

[0005] To achieve the above objectives, this utility model provides a calibration device for a mine negative pressure sensor, comprising a U-shaped pressure gauge and an air bladder connected by a three-way pipe; the remaining end of the three-way pipe is connected to the air inlet of the negative pressure sensor; the air bladder is provided with an air outlet and an air inlet, the air outlet being connected to the three-way pipe and the air inlet being connected to the outside; an air outlet valve is provided on the air outlet, which is a one-way valve that conducts from the air bladder to the three-way pipe; a tail valve is provided on the air inlet, which is a one-way valve that conducts from the outside to the air bladder.

[0006] With the above structure, the U-shaped manometer, the air bladder bulb, and the negative pressure sensor are connected via a three-way pipe, ensuring they are under equal pressure. During calibration, the operator can visually observe the pressure applied to the negative pressure sensor through the U-shaped manometer, thus accurately adjusting the pressure to 2.5 kPa, meeting the calibration requirements of the KGY3A mining negative pressure sensor and improving calibration accuracy. The air bladder bulb, as a pressure source, can be easily generated by squeezing it by hand. The one-way function of the outlet valve and tail valve ensures that when the air bladder bulb is squeezed, gas can only flow from the bulb to the three-way pipe, and then into the negative pressure sensor and U-shaped manometer, without leaking out from the inlet. When the air bladder bulb is released, outside air can only enter through the inlet, without drawing the squeezed gas back into the bulb. This design ensures stable pressure output and constant pressure maintenance, facilitating precise calibration operations for the operator.

[0007] Preferably, the three-way conduit includes a three-way tube, which is connected to the U-shaped manometer, the airbag bulb, and the air inlet of the negative pressure sensor via transparent flexible tubes. The transparent flexible tubes are flexible, easy to bend, and adaptable to connections in different scenarios.

[0008] Preferably, an air outlet is provided with an air outlet pipe, which is inserted into the air outlet and sealed to the side wall of the air outlet; an air outlet valve is fixedly installed in the air outlet pipe; an air inlet is provided with an air inlet pipe, which is inserted into the air inlet and sealed to the side wall of the air inlet; and a tail valve is fixedly installed in the air inlet pipe.

[0009] Preferably, a vent valve is provided on the vent pipe outside the vent valve.

[0010] Preferably, a filter screen is installed on the intake pipe outside the tail valve.

[0011] Preferably, the exhaust pipe and the intake pipe are made of metal.

[0012] Preferably, the exhaust valve and the tail valve have the same structure but are installed in opposite directions.

[0013] Preferably, the vent valve includes a valve body and a valve core installed inside the valve body; the valve body has a cylindrical structure and a valve cavity is provided inside; the inner side wall of the valve body is provided with a valve seat protruding into the valve cavity; the valve core includes a valve disc and a piston provided on both sides of the valve seat and a valve stem connecting the valve disc and the piston; the valve disc is provided with a through hole; a return spring is sleeved on the valve stem, the return spring is clamped between the valve disc and the valve seat, and under the action of the return spring, the piston is pressed against the upper surface of the valve seat and sealed with the valve seat; when the airflow impacts the piston from the bottom, the piston disengages from the valve seat, and the valve cavity is opened.

[0014] Preferably, the contact area between the valve seat and the piston is a conical surface.

[0015] Preferably, the piston includes a guide disc that can be inserted into the valve seat, and the piston is fixed above the guide disc; the diameter of the guide disc is smaller than the diameter of the valve seat bore.

[0016] After adopting the above technical solution, the beneficial effects of this utility model are:

[0017] This invention provides a calibration device for a mine negative pressure sensor, which solves the technical problem of high calibration difficulty of negative pressure sensors in the prior art. The device connects a U-shaped manometer, an air bladder, and the negative pressure sensor via a three-way pipe, ensuring that all three are under equal pressure. During calibration, the operator can directly observe the pressure value applied to the negative pressure sensor through the U-shaped manometer, thereby accurately adjusting the pressure to 2.5 kPa, meeting the calibration requirements of the KGY3A mine negative pressure sensor and improving calibration accuracy. Attached Figure Description

[0018] Figure 1 is a structural schematic diagram of a calibration device for a negative pressure sensor in a mine according to this utility model;

[0019] Figure 2 is a schematic diagram of the internal structure of the airbag in Figure 1;

[0020] Figure 3 is a schematic diagram of the internal structure of the vent valve;

[0021] Figure 4 is a schematic diagram of the valve core.

[0022] In the diagram, 1. U-shaped pressure gauge, 2. Air bladder bulb, 21. Air outlet, 22. Air inlet, 23. Air outlet pipe, 231. Air relief valve, 24. Air inlet pipe, 241. Filter screen, 3. Negative pressure sensor, 41. T-junction pipe, 51. Valve body, 511. Valve seat, 52. Valve core, 521. Valve disc, 522. Piston, 523. Valve stem, 53. Return spring. Detailed Implementation

[0023] The present invention will be further described below with reference to the accompanying drawings.

[0024] The orientations mentioned in this specification are based on the orientation of the calibration device for a mine negative pressure sensor under normal operation. They do not limit the orientation during storage and transportation, and only represent relative positional relationships, not absolute positional relationships.

[0025] As shown in Figure 1, a calibration device for a mine negative pressure sensor includes a U-shaped pressure gauge 1 and an air bladder 2 connected by a three-way pipe; the remaining end of the three-way pipe is connected to the air inlet of the negative pressure sensor 3.

[0026] The airbag bulb 2 is equipped with an air outlet 21 and an air inlet 22. A three-way pipe is connected to the air outlet 21, and the air inlet 22 is connected to the outside. An air outlet valve is installed on the air outlet 21. The air outlet valve is a one-way valve that allows air to pass from the airbag bulb 2 to the three-way pipe. A tail valve is installed on the air inlet 22. The tail valve is a one-way valve that allows air to pass from the outside to the airbag bulb 2.

[0027] The U-shaped pressure gauge 1, the air bladder bulb 2, and the negative pressure sensor 3 are connected via a three-way pipe, ensuring that all three are under equal pressure. During calibration, the operator can visually observe the pressure applied to the negative pressure sensor 3 through the U-shaped pressure gauge 1, thereby accurately adjusting the pressure to 2.5 kPa, meeting the calibration requirements of the KGY3A mining negative pressure sensor 3, and improving the accuracy of calibration.

[0028] The airbag bulb 2 serves as a pressure source, easily generating pressure by hand-squeezing. The one-way function of the outlet and tail valves ensures that when the airbag bulb 2 is squeezed, gas flows only from the bulb 2 to the three-way pipe, then into the negative pressure sensor 3 and the U-shaped pressure gauge 1, without leaking out from the inlet. When the airbag bulb 2 is released, outside air enters only through the inlet 22, without drawing the squeezed gas back into the bulb. This design guarantees stable pressure output and constant pressure maintenance, facilitating precise calibration by operators. This simple and direct connection method allows operators to quickly assemble and calibrate the device on-site, saving time and labor costs.

[0029] The three-way conduit includes a three-way pipe 41, which in this embodiment is a copper pipe. The three-way pipe 41 is connected to the U-shaped pressure gauge 1, the three-way pipe to the airbag bulb 2, and the three-way pipe to the air inlet of the negative pressure sensor 3 via transparent flexible tubes.

[0030] An air outlet 21 is provided with an air outlet pipe 23, which is inserted into the air outlet 21 and sealed to the side wall of the air outlet 21; an air outlet valve is fixedly installed in the air outlet pipe 23. An air inlet 22 is provided with an air inlet pipe 24, which is inserted into the air inlet 22 and sealed to the side wall of the air inlet 22; a tail valve is fixedly installed in the air inlet pipe 24. The air outlet pipe 23 and the air inlet pipe 24 are made of metal to ensure their structural strength and durability.

[0031] A vent valve 231 is installed on the vent pipe 23 outside the vent valve to release the pressure in the three-way pipe after calibration. In this embodiment, the vent valve 231 has the following structure: a threaded through hole is provided on the side wall of the vent pipe 23; the vent valve 231 is a sealing bolt that mates with the threaded through hole. When venting is required, the sealing bolt is unscrewed from the threaded through hole, allowing the threaded through hole to connect to the outside, thereby venting the air.

[0032] A filter screen 241 is installed on the intake pipe 24 outside the tail valve to prevent external impurities from entering the airbag bulb 2. The exhaust valve and tail valve have the same structure but are installed in opposite directions to achieve their respective one-way conduction functions.

[0033] As shown in Figures 2, 3, and 4, this is one structure of an exhaust valve. The exhaust valve includes a valve body 51 and a valve core 52 installed inside the valve body 51. The valve body 51 has a cylindrical structure and a valve cavity inside; the valve body 51 is installed inside the exhaust pipe 23 and is sealed to the inner wall of the exhaust pipe 23. A valve seat 511 protruding into the inner cavity of the valve body 51 is provided on the inner side wall of the valve body 51.

[0034] The valve core 52 includes a valve disc 521 and a piston 522 disposed on both sides of the valve seat 511, and a valve stem 523 connecting the valve disc 521 and the piston 522. The valve disc 521 has a hollow structure to ensure smooth gas flow; in this embodiment, the valve disc 521 has a cross structure. A return spring 53 is sleeved on the valve stem 523, and the return spring 53 is clamped between the valve disc 521 and the valve seat 511. Under the action of the return spring 53, the piston 522 is pressed against the upper surface of the valve seat 511, sealing it; when the airflow impacts the piston 522 from the bottom, the piston 522 disengages from the valve seat 511, and the valve chamber is opened.

[0035] The valve core 52 of the exhaust valve, through the cooperation of the return spring 53 and the piston 522, achieves precise control of gas flow. Under normal circumstances, the piston 522 is pressed against the valve seat 511 by the return spring 53, achieving a seal; when the airflow impacts the piston 522 from the bottom, the piston 522 disengages from the valve seat 511, the valve chamber is opened, and the gas can flow out smoothly. This design ensures the sensitivity and reliability of the exhaust valve, enabling it to accurately respond to the squeezing operation of the airbag bulb 2.

[0036] Furthermore, the contact area between the valve seat 511 and the piston 522 is a conical surface, which increases the contact area between the piston 522 and the valve seat 511, improves the sealing effect, prevents gas leakage, and ensures stable pressure output.

[0037] The piston 522 includes a guide disc that can be inserted into the valve seat 511, and the piston 522 is fixed above the guide disc; the diameter of the guide disc is smaller than the inner diameter of the valve seat 511, which facilitates the movement of the piston 522 within the valve seat 511. The guide disc enhances the strength of the piston 522.

[0038] As shown in Figures 1-4, the working process of a calibration device for a mine negative pressure sensor is as follows:

[0039] Use the remote control to set the negative pressure sensor 3 to the calibration position. According to the calibration requirements of the KGY3A mining negative pressure sensor, first perform zero-point calibration.

[0040] Pressing the airbag bulb 2 forces the gas inside the airbag bulb 2 out through the air outlet valve. At this time, the air outlet valve opens, and the gas flows from the air outlet 21 to the three-way pipe, and then into the negative pressure sensor 3 and the U-shaped pressure gauge 1. At this time, the tail valve closes to prevent the gas from being discharged from the air inlet 22.

[0041] When the airbag bulb 2 is released, the tail valve opens, and gas is drawn into the airbag bulb 2 through the air inlet 22. At this time, the outlet valve closes to prevent gas from being drawn back into the airbag bulb 2 through the three-way pipe. The filter screen 241 on the air inlet pipe 24 can filter out impurities in the air.

[0042] Repeatedly squeeze the airbag bulb 2 and observe the scale of the U-shaped pressure gauge 1 until it displays 2.5 kPa and remains stable. Then stop the gripping operation. Use the remote control to adjust the negative pressure sensor reading to 2.5 kPa, press the "Exit" button to save, and the negative pressure sensor calibration is now complete.

[0043] Of course, the above description is not intended to limit the present utility model, and the present utility model is not limited to the examples given above. Any changes, modifications, additions or substitutions made by those skilled in the art within the scope of the present utility model should also fall within the protection scope of the present utility model.

Claims

1. A calibration device for a negative pressure sensor used in mining, characterized in that: The device includes a U-shaped pressure gauge and an airbag bulb connected by a three-way pipe; the remaining end of the three-way pipe is connected to the air inlet of a negative pressure sensor; the airbag bulb is provided with an air outlet and an air inlet, the air outlet is connected to the three-way pipe, and the air inlet is connected to the outside; the air outlet is provided with an air outlet valve, which is a one-way valve that conducts from the airbag bulb to the three-way pipe; the air inlet is provided with a tail valve, which is a one-way valve that conducts from the outside to the airbag bulb.

2. The calibration device for a mine negative pressure sensor according to claim 1, characterized in that: The three-way pipeline includes a three-way pipe, which is connected to the U-shaped pressure gauge, the air bladder bulb, and the air inlet of the negative pressure sensor via transparent flexible tubes.

3. The calibration device for a mine negative pressure sensor according to claim 1, characterized in that: An air outlet is provided with an air outlet pipe, which is inserted into the air outlet and sealed to the side wall of the air outlet; an air outlet valve is fixedly installed in the air outlet pipe; an air inlet is provided with an air inlet pipe, which is inserted into the air inlet and sealed to the side wall of the air inlet; and a tail valve is fixedly installed in the air inlet pipe.

4. The calibration device for a mine negative pressure sensor according to claim 3, characterized in that: A vent valve is provided on the vent pipe outside the vent valve.

5. The calibration device for a mine negative pressure sensor according to claim 3, characterized in that: A filter screen is installed on the intake pipe outside the tail valve.

6. The calibration device for a mine negative pressure sensor according to claim 3, characterized in that: The exhaust pipe and the intake pipe are made of metal.

7. The calibration device for a mine negative pressure sensor according to claim 1, characterized in that: The exhaust valve and the tail valve have the same structure but are installed in opposite directions.

8. The calibration device for a mine negative pressure sensor according to claim 1, characterized in that: The vent valve includes a valve body and a valve core installed inside the valve body; the valve body has a cylindrical structure with a valve cavity inside; the inner side wall of the valve body has a valve seat protruding into the inner cavity of the valve body; the valve core includes a valve disc and a piston disposed on both sides of the valve seat, and a valve stem connecting the valve disc and the piston; the valve disc has a through hole; a return spring is sleeved on the valve stem, the return spring is clamped between the valve disc and the valve seat, and under the action of the return spring, the piston abuts against the upper surface of the valve seat, sealing with the valve seat; when the airflow impacts the piston from the bottom, the piston disengages from the valve seat, and the valve cavity is opened.

9. A calibration device for a mine negative pressure sensor according to claim 8, characterized in that: The contact point between the valve seat and the piston is a conical surface.

10. A calibration device for a mine negative pressure sensor according to claim 8, characterized in that: The piston includes a guide disc that can be inserted into the valve seat, and the piston is fixed above the guide disc; the diameter of the guide disc is smaller than the diameter of the inner bore of the valve seat.

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